1. Field of the Invention
The present invention relates to a wireless communication system, and more particularly, to a method for transmitting an uplink pilot signal in a wireless communication system and an apparatus therefor.
2. Discussion of the Related Art
FIG. 1 shows a wireless communication system. Referring to FIG. 1, the wireless communication system 100 includes a plurality of base stations 110 and a plurality of terminals 120. The wireless communication system 100 may include a homogeneous network or a heterogeneous network. The heterogeneous network refers to a network in which different network entities such as a macro cell, a femto cell, a pico cell and a repeater coexist. The base station is generally a fixed station communicating with a terminal, and base stations 110a, 110b and 110c provide services to specific geographical areas 102a, 102b and 102c. In order to improve system performance, a specific area may be divided into smaller areas 104a, 104b and 104c. Each of the smaller areas may be referred to as a cell, a sector or a segment. In an IEEE 802.16 system, a cell identity (Cell_ID or IDCell) is given based on the overall system. In contrast, a sector or segment identity is given based on a specific area, to which each base station provides a service, and has values of 0 to 2. The terminal 120 is generally distributed in the wireless communication system and may be fixed or moved. Each terminal may communicate with one or more base stations through an uplink (UL) and a downlink (DL) at a certain instant. The base station and the terminal may perform communication using Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Code Division Multiple Access (CDMA), Single Carrier-FDMA (SC-FDMA), Multi Carrier-FDMA (MC-FDMA), Orthogonal Frequency Division Multiple Access (OFDMA) or a combination thereof. In the present specification, the term “uplink” refers to a communication link from a terminal to a base station and the term “downlink” refers to a communication link from a base station to a terminal.